Following a landmark workshop on RDF validation in 2013, two languages have emerged for describing the "shape" of graph structures for the purpose of validating RDF data. The Shape Expressions Language (ShEx) and Shapes Constraint Language (SHACL) provide languages for expressing constraints against which graphs of RDF triples can be compared. These languages support the expression of a Dublin Core™ application profile in a manner that can directly be used for validating metadata based on the profile.